One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10,14,12)(11,15,17,18)(13,16,21,20)(19,22,23,24)(25,26)(27,35)(28,37)(29,33)(30,36)(31,32)(34,38)(39,40)(3,7)(6,8)(9,11)(10,15)(12,18)(13,19)(14,17)(16,22)(20,24)(21,23)(26,32)(28,38)(33,35)(36,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(11,17)(15,18)(19,23)(22,24)(25,27,31,29)(26,33,32,35)(28,36,38,39)(30,37,40,34)(1,3,4,7)(2,6,5,8)(9,12,14,10)(11,18,17,15)(13,16,21,20)(19,22,23,24)(25,28)(26,34)(27,36)(29,39)(30,33)(31,38)(32,37)(35,40)(1,2)(3,6)(4,5)(7,8)(9,13)(10,16)(11,19)(12,20)(14,21)(15,22)(17,23)(18,24)(25,29,31,27)(26,35,32,33)(28,36,38,39)(30,37,40,34)(9,11)(10,15)(12,18)(13,19)(14,17)(16,22)(20,24)(21,23)(25,30)(26,36)(27,34)(28,33)(29,37)(31,40)(32,39)(35,38) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.